I use this product to rack mount a GAP Pre 73 DLX and a GAP Comp 54.
It does what you would expect...holds 2 1/2 rack units in a 1U rack space.
Stability:
There are reports of this being too "tall" to fit perfectly but I have not had this experience. Most that report that havent gotten their screws in place and if you find yourself in this situation, check your mount screws. The units fit in snuggly and are protected in the rack so like a can of Ronseal, it does exactly like it says on the tin!
Quality:
The metal feels solid and the screws fit perfectly. Nothing much to say here but that it doesnt feel cheap. It fitted in my 6U rack perfectly and still does to this day.
Conclusion:
This is the only option for mounting 2 GAP products in a 1U space. There are no instructions with it, but its easy to figure out. Requires a screwdriver, obviously, so dont forget that when you're putting it all together.
For me though, it is a little expensive for what it does and is a bit of a hidden cost for GAP products, because lets face it, most of us with one of these will want to rack mount it. For this reason it loses a star, but it is the only product that I know of that will allow you to rack mount any GAP (1/2U wide) products